1. My Volvo stopped (all the lights came on the inside dash) and I had it towed to my mechanic on Jan. 10.
a.. He sent it out to another place that specialized in Volvo's (only newer ones); that mechanic found the wiring was bad leading to the fuel pump, so he replaced it.
2. My mechanic then replaced the fuel pump & sent me on my way on Jan. 13. I told him it was making a humming noise before I left his garage, he said it would go away after I drove it for a while. It also started jerking slightly when I put my foot on the gas.
3. He ordered a brand new fuel pump and I went back in and he replaced it with the new one on Jan. 18. I called and said, the noise and jerking is still happening.
4. I went back on Jan. 23 and he confirmed the noise was the regulator and would locate one for me.
5. I returned as he ordered a regulator and installed it for me on Feb. 1. He told me it was making a noise still but should go away after driving it 5 miles or so, it never went away. If anything, it got worse.
Is it harmful to drive it this way? It never did that before. What could it be?? I need to get this car running ASAP. I'm tapped out on making trip after trip for the same thing.
Does anyone know a good classic Volvo mechanic nearby Sherman Oaks, California? Thnx!

 

From the sounds of your problem it may be that the in-tank pump isn't working. Now I'm not familiar at all with '79 model year as it had the CIS fuel injection but I think they still had two pumps - one in the tank and external. Typically when the in-tank pump fails, the main pump gets noisy since it has to work harder. It will also wear out quicker and may not be able to provide the needed fuel pressure under loads. These are all the symptoms you have.

Your Volvo "specialist" should know this so I think it is a good idea to find another.

 

Thank you so much for your expertise! Now that you mention it, I do recall having to clear out my trunk a decade or so ago for a pump to be replaced. That's the problem I bet you are right on... I have called the place that did it last time from the trunk and am getting an estimate from them now. He's looking for the part and stated $80 for labor. I paid $589 for wiring (an outside Volvo specialist), the one fuel pump & regulator (from this mechanic who hasn't completed the job), does that sound high or about right? Again, thank you!!

***** After having replaced (1) the wiring leading up to the fuel pump, (2) the exterior fuel pump, (3) the fuel pressure regulator and (4) fuel filter, you were absolutely right on it was (5) the in-tank pump from the trunk probably from the start. Oh, I wished I would have posted this much earlier on. I could have saved some money; however, the car is running the best it has in a long time so maybe it was time to replace all. I notice a big difference when I shut it off. The in-tank pump hose had broken loose (worn out) and the gas was not flowing properly, which caused my car to shut off. I need to marry a mechanic!